solving environmental problems one equation at a time

Risk of death by sharks vs. walking

In a comment on my previous post about shark attacks, I said that perhaps we should walk to the beach to lower our risk of death due to traffic fatalities. I’m glad Kevin Lawrence, correctly pointed out that in order to make that claim, I’d have to look at pedestrian fatality statistics.

Well, good thing I did. It turns out walking is way more dangerous than driving (per mile, but not per minute).

There are roughly 42 billion walking trips in the USA per year*. And on average those trips tend to be roughly about one mile*. There are 5,376 pedestrian fatalities per year (compared to about 38,000 auto-accident fatalities in general, which likely includes the pedestrian figure). These figures leed to about 0.000000128 deaths per mile walked. This means that walking 0.08 miles has roughly the same fatality risk as one beach visit due to a shark attack. So your house would have to be less than 65 meters away from the beach for the walking trip (round trip) to be less dangerous than the beach visit.

In many cases, 65 meters is longer than the distance between the beach and our parked cars! The walk from your car to the beach might be more dangerous than dying from a shark attack***.

*** There are of course a lot of caveats here, as parking spots close to the beach might be in dedicated parking lots, and not involve crossing busy intersections. But even so, this number is quite stunning.